Seasonal evaluation of culturable bioaerosols and airborne particulate matter in Iranian hospital wards using a Monte Carlo health risk model.

This study aimed to measure fine particulate matter (PM) concentrations and culturable bioaerosols (bacteria and fungi) in the indoor air of operating (OR) and emergency (EM) rooms, as well as internal wards (INT) in hospitals in Bushehr city, Iran. For the first time, the Monte Carlo model was employed to assess health risks associated with PM release into hospital indoor air, focusing on healthcare workers. A four-stage impactor and a one-step Anderson contact sampler were used to determine PM and bioaerosols, respectively. To assess the non-cancer risk associated with contaminants (PM), we calculated the Hazard Quotient (HQ). This evaluation was conducted using Crystal Ball software, which performed 1000 independent iterations at a 95% confidence level. The highest PM concentration recorded was 115.6 μg/m3 in the EM. Based on the results of the Monte Carlo, most calculated hazard quotient (HQ) values exceeded acceptable levels (< 1) for staff. The maximum concentrations of bacteria and fungi were 767 and 776 cfu/m3 in the EM during summer. A positive correlation was found between fungal levels and humidity in hospital wards. Additionally, PM concentrations of larger sizes and bacteria increased during visiting hours. Most bioaerosol concentrations were above the standard values recommended by WHO. As a result of this study, continuous monitoring and control of indoor air pollutants in these environments are vital to prevent various diseases in healthcare employees and patients.